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Bulk Email Validation API (x402-gateway.blackwoodstate8.workers.dev)
x402
Bulk Email Validation API (x402-gateway.blackwoodstate8.workers.dev) is a paid API for AI agents from x402-gateway.blackwoodstate8.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-23).
Validates up to 20 email addresses per call, checking syntax, MX records, disposable/free/role flags, SPF, DMARC, and returning a verdict for each address.
Price / call$0.02
Success—
StatusUnknown
How this service works
Use when you need bulk email validation, email list verification or to verify email lists before a send or import. Do not use for one address (email-check is cheaper), proving a mailbox exists (no SMTP probe) or sending email. Returns JSON checking up to 20 email addresses in one call: syntax, MX records, disposable, free and role flags, SPF, DMARC and a verdict each, plus counts by verdict for 0.02 USDC per call. Typical response time 2500 ms (p95). Category: Data.
Output
Returns a JSON object with a results array (one entry per email address) containing: normalized email, syntax validity, domain, MX records, disposable/free provider/role account flags, domain existence, SPF and DMARC records and policy, a per-address verdict, reasons for the verdict, and whether SMTP was checked. Also includes aggregate summary counts by verdict and the number of unique domains checked.
Example use cases
Pre-send email list scrub
“I'm about to send a marketing campaign to these 15 addresses — can you verify them all for deliverability and flag any disposable, role-based, or invalid ones before I hit send? Here's the list: [alice@example.com, info@acme.com, noreply@widgets.io ...]”
New user signup fraud check
“We just got 12 new signups and I want to make sure they're not using throwaway or fake emails — can you validate all of them at once and tell me which ones look suspicious or disposable?”
CRM import quality gate
“Before we import this batch of 18 prospect emails into our CRM, run them through validation and tell me which ones have bad syntax, missing MX records, or belong to free email providers so we can clean the list first.”
Technical details
Endpoint
POSThttps://x402-gateway.blackwoodstate8.workers.dev/v1/email-batch?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to validate between 2 and 20 email addresses in a single call and want comprehensive checks including syntax, DNS/MX, disposable detection, role-account flagging, SPF and DMARC analysis. Prefer this over single-address email-check endpoints when working with lists; it is more cost-efficient per address at scale. Do not use this if you need SMTP probing to confirm a specific mailbox exists, if you need to send email, or if you only have one address (a cheaper single-check endpoint may be preferable).
Side effects
- More than 20 emails submitted — returns validation error
- Invalid email string format in array — individual entry marked syntax invalid
- Domain with no MX records — mx array empty, acceptsMail false
- DMARC/SPF lookup timeout — fields may be null
- Network timeout for DNS lookups within the 2500ms p95 window
- Payment not attached or insufficient — x402 payment required error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"count": 4,
"domains": 3,
"results": [
{
"mx": [
{
"host": "mx.ietf.org",
"priority": 0
}
],
"spf": "v=spf1 ip4:166.84.6.31 ip4:166.84.7.238 ip6:2602:f977:800:f7f6::/64 ip4:166.84.7.34 ip6:2602:f977:800::e276:63ff:fe66:3400 include:_spf.google.com include:spf.hostedrt.com ~all",
"dmarc": "v=DMARC1; p=none; rua=mailto:dmarc_agg@vali.email,mailto:dmarc-report@ietf.org",
"email": "postmaster@ietf.org",
"domain": "ietf.org",
"reasons": [
"role_account"
],
"verdict": "deliverable_domain",
"disposable": false,
"normalized": "postmaster@ietf.org",
"acceptsMail": true,
"dmarcPolicy": "none",
"roleAccount": true,
"smtpChecked": false,
"syntaxValid": true,
"domainExists": true,
"freeProvider": false
},
{
"mx": [
{
"host": "mail.mailinator.com",
"priority": 1
},
{
"host": "mail2.mailinator.com",
"priority": 1
}
],
"spf": "v=spf1 -all",
"dmarc": "v=DMARC1;p=reject;sp=reject;aspf=s;pct=100",
"email": "test@mailinator.com",
"domain": "mailinator.com",
"reasons": [
"disposable"
],
"verdict": "risky",
"disposable": true,
"normalized": "test@mailinator.com",
"acceptsMail": true,
"dmarcPolicy": "reject",
"roleAccount": false,
"smtpChecked": false,
"syntaxValid": true,
"domainExists": true,
"freeProvider": false
},
{
"mx": [],
"spf": "v=spf1 -all",
"dmarc": "v=DMARC1;p=reject;sp=reject;adkim=s;aspf=s",
"email": "info@example.com",
"domain": "example.com",
"reasons": [
"null_mx",
"role_account"
],
"verdict": "undeliverable",
"disposable": false,
"normalized": "info@example.com",
"acceptsMail": false,
"dmarcPolicy": "reject",
"roleAccount": true,
"smtpChecked": false,
"syntaxValid": true,
"domainExists": true,
"freeProvider": false
},
{
"mx": [],
"spf": null,
"dmarc": null,
"email": "not-an-email",
"domain": null,
"reasons": [
"syntax"
],
"verdict": "invalid",
"disposable": false,
"normalized": null,
"acceptsMail": false,
"dmarcPolicy": null,
"roleAccount": false,
"smtpChecked": false,
"syntaxValid": false,
"domainExists": null,
"freeProvider": false
}
],
"summary": {
"risky": 1,
"invalid": 1,
"unknown": 0,
"undeliverable": 1,
"deliverable_domain": 1
}
}
}Tags
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